How do I keep tile sealant from dissipating?
 

This is a tile paio that I am having to reseal for the 3rd time. I have tried letting the tile dry for 3 days in the dead heat of the summer before applying the sealant; however, it does not seem to be working. Here are some pictures to possibly help construct an analysis as to why the sealant will not sustain on this tile. Thanks

Have you tryed the same sealer each time? What types.